练习: 设ln=2sin”xx,已知ln=n2,求l和l6 解12=41=421=32 sin xdx==-8c0x=8 =5164264248b4=的分, 5353115r5y 482 上页 下页
上页 返回 下页 设 = 2 0 sin I xdx n n 已知 2 1 − − n = n I n n I 求 I5和 I6 练习： 解 15 8 cos 15 8 sin 15 8 3 2 5 4 5 4 2 0 2 0 5 = 3 = 1 = =− = I I I xdx x 48 2 15 48 15 2 1 4 3 6 5 4 3 6 5 6 5 2 0 6 4 2 0 = = = = = I I I I dx 15 8 cos 15 8 sin 15 8 3 2 5 4 5 4 2 0 2 0 5 = 3 = 1 = =− = I I I xdx x 15 8 cos 15 8 sin 15 8 3 2 5 4 5 4 2 0 2 0 5 = 3 = 1 = =− = I I I xdx x 15 8 cos 15 8 sin 15 8 3 2 5 4 5 4 2 0 2 0 5 = 3 = 1 = =− = I I I xdx x 48 2 15 48 15 2 1 4 3 6 5 4 3 6 5 6 5 2 0 6 4 2 0 = = = = = I I I I dx 48 2 15 48 15 2 1 4 3 6 5 4 3 6 5 6 5 2 0 6 4 2 0 = = = = = I I I I dx 48 2 15 48 15 2 1 4 3 6 5 4 3 6 5 6 5 2 0 6 4 2 0 = = = = = I I I I dx 48 2 15 48 15 2 1 4 3 6 5 4 3 6 5 6 5 2 0 6 4 2 0 = = = = = I I I I dx